Lin Herng-Ching, Chen Chin-Shyan, Xirasagar Sudha, Lee Hsin-Chien
School of Health Care Administration, Taipei Medical University, Taipei, Taiwan.
Neuropsychobiology. 2008;57(1-2):32-7. doi: 10.1159/000129664. Epub 2008 May 2.
Using 7-year population-based data on Taiwan, we examined seasonal variation in violent versus nonviolent suicide, and its association with meteorological factors: ambient temperature, relative humidity, atmospheric pressure, rainfall and daily sunshine hours.
We used Taiwan's nationwide mortality data from 1997 to 2003, categorizing the sample decedents into two groups, violent (ICD-9-CM codes E953-E958) and nonviolent (E950-E952) suicide, based on the suicide method used. Seasonal autoregressive integrated moving average (SARIMA) modeling was used to detect seasonality of suicide, and the association of climate variables with violent versus nonviolent suicide.
The SARIMA test of seasonality was significant for both genders and the pooled sample (all p < 0.001) in violent suicide deaths, but not nonviolent suicides. Seasonal trends show a significant peak in March-May (early to late spring) for violent suicides. Increasing ambient temperature predicted increasing violent suicide rates.
We conclude that seasonality exists in violent but not nonviolent suicide rates. Our findings suggest that suicide is a heterogeneous phenomenon and violent suicide may be more influenced by biochemical and chronobiological mechanisms.
利用台湾地区基于人群的7年数据，我们研究了暴力自杀与非暴力自杀的季节性变化及其与气象因素（环境温度、相对湿度、大气压力、降雨量和每日日照时长）的关联。
我们使用了台湾地区1997年至2003年的全国死亡率数据，根据自杀方式将样本死者分为两组，即暴力自杀（国际疾病分类第九版临床修订本编码E953-E958）和非暴力自杀（E950-E952）。采用季节性自回归积分滑动平均（SARIMA）模型检测自杀的季节性以及气候变量与暴力自杀和非暴力自杀的关联。
暴力自杀死亡中，季节性的SARIMA检验对男性、女性及合并样本均具有显著性（所有p<0.001），而非暴力自杀则不然。季节性趋势显示，暴力自杀在3月至5月（早春到晚春）有一个显著高峰。环境温度升高预示着暴力自杀率上升。
我们得出结论，暴力自杀率存在季节性，而非暴力自杀率不存在。我们的研究结果表明，自杀是一种异质性现象，暴力自杀可能更受生化和生物钟机制的影响。
